The present invention relates to a method for controlling a power gain.
When outputting a transmitted signal from a mobile radio device, the output power is increased continuously to a preset power level at the beginning of the transmitted signal, and the preset power is continuously decreased at the end of the transmitted signal, as is described in xe2x80x9cEuropean Digital Cellular Telecommunications System (Phase 2), Radio Transmission and Reception (GSM 05.05), European Telecommunication Standard, May 1994xe2x80x9d.
The method according to the present invention having the features of the main claim has an advantage over the related art in that only a single reference control signal is needed for outputting the transmitted signal, even at different presettable power levels. This means that only a small number of memory locations is needed for storing discrete control signal amplitude values.
The features listed in the subclaims provide advantageous embodiments and refinements of the method described in the main claim.
It is advantageous to limit the control signal to a preset maximum value in order to set the preset power for outputting the transmitted signal, for which purpose the reference control signal is compared to the preset maximum control signal value at specific times or continuously, and/or the control signal is limited to the preset maximum control signal value after a preset signal rise time. By doing this, the control signal for setting the target output power of the transmitted signal can be very easily determined, because no complicated arithmetic operations, such as multiplication, are needed, but rather only comparison operations.
It is especially advantageous to switch from the reference control signal to the preset maximum control signal value to limit the control signal. This provides an especially simple means for limiting the control signal to the preset maximum control signal value.
It is also advantageous to output the transmitted signals with preset time offsets as a function of the preset power. This makes it possible to maintain a preset time template for outputting the transmitted signal at different preset power levels.
A further advantage is the ability to easily provide time offsets of this type by delaying the beginning of the transmitted signal.
It is also advantageous to define the intervals between the times at which the reference control signal is compared to the preset maximum control signal value. By defining the intervals in this manner throughout the entire period of transmitted signal output or only during output segments, the time at which the signal starts to fall as well as the rate of rise of the necessary control signal can be easily and flexibly adjusted to the requirements.
It is also advantageous to select the number of reference control signal values assumed by the control signal as a function of the preset power. This makes it possible to skip reference control signal values which exceed the preset maximum control signal value in an easy and uncomplicated manner.
It is further advantageous to determine the actual output power achieved at the output of the power amplification circuit with the aid of a detector and return it to a control loop of the power amplification circuit in the form of a controlled variable. This procedure is an easy way to control the output power.